In the related art, there is a known fluoroscopy apparatus that is capable of obtaining a high-luminance fluorescence image of a lesion by radiating excitation light, which excites fluorescent dye to generate agent-fluorescence, onto an observation target site, to which a fluorescent dye that specifically accumulates at a lesion, such as cancer cells, is administered, and by capturing the agent-fluorescence generated (for example, see Patent Literature 1).
In the fluoroscopy apparatus described in Patent Literature 1, since the intensity of the excitation light radiated onto an observation target site varies depending on distance, in order to correct the influence due to the distance, arithmetic processing in which a fluorescence image of the observation target site is divided by a reflected-light image of the same observation target site is performed.